Potentiation of dipsogenic actions by centrally administered type-C natriuretic peptide in spontaneously hypertensive but not Wistar-Kyoto rats.

1. The effects of type-C natriuretic polypeptides (CNP) on the central dipsogenic and pressor responses to angiotensin II (AngII) were studied by the administration of agents into the lateral cerebral ventricle under conscious and unrestrained conditions in normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). 2. The fluid intake induced by AngII (25 ng) and water deprivation were potentiated after pretreatment with CNP in SHR but not in WKY rats. However, carbachol-induced water intake was not altered by pretreatment with CNP (2.5 micrograms) in either WKY rats or SHR. 3. In contrast, CNP did not influence the pressor responses to AngII in either WKY rats or SHR.